Some tips I'd give is to first think of an overall theme or message from your story. Like what is the lesson the main character has learned that the reader could also learn too. Grabbing the reader with a great overall message is always a plus. To me personally, the subscriber count and upvote count doesn't matter all that much to me. In other words, yes I appreciate it and all and it shows that people enjoy my story and own creativeness. But I feel like people care about it because it shows how popular their story is. I think that if you just have a great story that fangirls enjoy reading about then the stats shouldn't scare you. Although, if you do care about that stuff, writing about a very popular idol(s) atm grabs everyone's attention. So the amount of interest the idol(s) you're writing about does make a difference. I think that overall, have fun writing! It's your fantasy coming to life! Write about what you love then writing will be easier and way more fun because you have that passion for it. Let your crazy inner fangirl mere imaginations come to life here at AFF!

Make sure that if you start your story, you will also end it. Don't be like other authors who keeps on hanging their stories for too long. And keep on updating. hehehe

Interesting storyline. And try not to put much information about the characters at your foreword because it won't give any surprises to your story. Readers love surprises and love a story that make them to wonder what is going to happen next.
And be creative. :)

Use different words every time, maybe with the help of google translate if needed.If you use Google tr. put only in ONE word instead of a whole sentence. Read english books, especially more difficult ones to get a larger vocabulary.
Put down a lot of time on each chapter, especially the first one because that's the one who will decide if the reader will continue reading. Re read them a few times because you will always find errors. I guess the rest, subbies and such comes after a while if you've put down a lot of time on your stories. Hard work is easily seen when reading. :)

For writing, I suggest that you read a lot of books first. While reading books, you can also learn how authors write and learn more descriptive words. When writing, you need to be clear on what the plot is. For the chapters, write out your feelings. Make sure to be extremely descriptive and don't use too many words twice. As for subscribers and voters, there are no techniques. It depends on your story and whether it attracts reader or not. Other than that I have nothing more for you ^^